The International Commission on Zoological Nomenclature (2003) ruled that the name for this wild species is not invalid by virtue of its being antedated by a name based on a domestic form. Therefore, IUCN considers the wild forms of Water Buffalo under Bubalus arnee, while the domestic forms are considered under B. bubalis (see Gentry et al. 2004). Despite this, Grubb (2005) listed arnee as a subspecies of bubalis, contrary to most authors. Three subspecies were recognized, all still apparently extant, by Groves (1996): B. a. arnee (much of India and Nepal); B. a. fulvus (Assam and neighbouring areas); and B. a. theerapati (South-east Asia).

Wild Water Buffalo is listed as Endangered A2de+3de; C1. The remaining world population totals under 4,000, with an estimate of fewer than 2,500 mature individuals. An inferred population reduction of at least 50% over the last three generations (generation length estimated at 8–10 years) seems likely given the severity of the threats, especially hybridization; it is projected to continue into the future.

During the Pleistocene epoch the genus Bubalus was widely distributed throughout Europe and southern Asia and contained forms conspecific with B. arnee. When the climate became drier the genus became restricted to the Indian subcontinent, mainland South-east Asia, and some of the South-east Asian islands. In historical times B. arnee ranged across South and South-east Asia, occurring from Mesopotamia to Indochina (Esptein 1971, Mason 1974, Cockrill 1984). 

Remnant populations of Wild Water Buffalo are thought to occur at single sites in each of southern Nepal, southern Bhutan, western Thailand, eastern Cambodia, and northern Myanmar, and at several sites in India: in the Central India and the North-east, predominantly in Assam.

Wild Water Buffalo is believed to be extinct in Bangladesh, Peninsular Malaysia, and on the islands of Sumatra, Java, and Borneo. The domestic form (considered by IUCN as B. bubalis) occurs as feral and domesticated populations worldwide (Grubb 2005).

Although the species has been speculated to have become extinct in Viet Nam, Myanmar and Cambodia (Corbet and Hill 1992), relatively recent surveys have revealed the confirmed presence of Wild Water Buffalo populations in Cambodia. Another recent survey along the Indo-Myanmar border confirmed the presence of small  possibly remnant subpopulations of free ranging buffaloes along the Balong river in Sagaing state of Myanmar (from Choudhury 2010). Wild living water buffaloes in the Hukaung Valley, of northern Myanmar may or may not be of largely or purely Wild Water Buffalo origin (J.W. Duckworth pers. comm. 2006). 

The origin and current genetic status of the herds of apparently wild buffaloes in Sri Lanka is uncertain but it is thought unlikely that any true wild buffaloes remain there today. Corbet and Hill (1992) included Sri Lanka within the historical range of Wild Water Buffalo, although Ellerman and Morrison-Scott (1951), Gee (1964), and Maia (1970) thought that the Sri Lankan buffaloes were descended from introduced domestic stock. Certain ancient texts seem to support this view (Ashby and Santiapillai 1983). The fact that no buffaloes occur south of the Godavari river in India has also been taken to suggest that Sri Lanka possesses only feral buffaloes descended from introduced animals. However, Deraniyagala (1953), considered that the occurrence of fossil buffalo teeth in the gem sands of the Ratnapura area disproved this view, although it is not clear how old these buffalo teeth are (and Gaur remains found at similar depths in the same area were less than 1,000 years old). Moreover, morphometrics suggest that there was an ancestral population of animals on that island closer to Wild Water Buffalo than to Domestic Water Buffalo (Groves and Jayantha Jayawardene unpublished). Nevertheless, even if the Water Buffalo is indigenous to Sri Lanka the question of whether the free-living herds found there today should be treated as wild B. arnee still arises. In the nineteenth-century, free-ranging herds were common over much of the island’s dry low country but they were nearly eliminated by an outbreak of rinderpest at the end of the century, and for a time their survival was in doubt (Phillips 1935). Phillips reported that small populations might have survived in the hill country but the subsequent intensification of agriculture probably led to their demise (Ashby and Santiapillai 1983). After the rinderpest outbreak buffalo recolonized much of the dry zone but most of the animals had apparently interbred with domestic stock and in 1953 Deraniyagala wrote ‘[the] relatively purest herds are restricted to Yala Game Sanctuary, but much vigilance will be necessary if this remnant is to be kept free from domestic animals which are now encroaching upon this once inaccessible area’. Woodford (1979) also suggested that the genetic integrity of the wild form has already been lost in Ruhuna. To conclude, even if it is assumed that Wild Water Buffalo once occurred on Sri Lanka it seems unlikely that it survived the rinderpest outbreak and the subsequent genetic swamping by feral and domestic buffaloes: consequently all free-living buffalo populations on Sri Lanka almost certainly contain genetic input from domestic or feral stock.

Neither Java nor Sumatra are included within the original range of wild Bubalus arnee as presented in many accounts. Nevertheless Stremme (1911) thought that the occurrence of the fossil B. palaeokerabau in Java made it probable that the buffaloes there belonged to the original fauna of the island (as Cuvier believed). Merkens (1927) also doubted, on historical grounds, the domestic origin of all free-living buffaloes on the island as did Mason (1974) who stated that domestic buffalo were present on Sumatra and Java long before the Hindus arrived almost 2,000 years ago. Moreover van der Maarel (1932) provisionally regarded the fossil specimens which he obtained from Java (and indeed B. palaeokerabau) as specifically indistinct from modern buffaloes, pointing to a Pleistocene presence of the species on the island (cf. Medway 1972). Corbet and Hill (1992) also thought it probable that wild buffaloes occur on Java and Sumatra. Despite the doubts raised by van der Maarel and Dammerman there is in fact little doubt that all the apparently wild buffaloes now living on Java and Sumatra are descended from domestic animals, or from Wild Water Buffaloes that have interbred with domestic and/or feral buffaloes (S. Hedges pers. comm. 2008).

Opinion is divided over whether to include Borneo within the historic range of the species. Corbet and Hill (1992) did not list it, and neither Mason (1974) nor Payne et al. (1985) considered it likely that Water Buffalo was part of the indigenous fauna. Lydekker (1898), by contrast, described the small buffalo of Sarawak as a separate subspecies (B. b. hosei), although Mason (1974) thought that Lydekker was probably describing the feral animals which were common there. Cockrill (1968) suggested that traders from the Hindu empire in Sumatra may have introduced the buffalo in the twelfth and thirteenth centuries and he did not think that there was any convincing evidence that would suggest that it was an indigenous species. Nevertheless, animal remains from the Niah caves indicate a Stone Age presence of buffalo in Sarawak (Harrisson 1961). Van Strien (1986) also considered it probable that Bubalus bubalis was part of the original fauna of the island and gave north-west Borneo as its current distribution. Harrisson, however, thought that the wild form was extinct. Feral (and semi-feral) buffaloes were formerly numerous throughout Borneo but the current status of the island’s feral population is poorly known. What does seem certain, however, is that even if the species is indigenous to the island (as seems to be the case) no true wild B. arnee occur there today since such animals would have been genetically swamped by the numerous feral animals some of which were descended from buffaloes introduced from outside Borneo (S. Hedges pers. comm. 2008).

The total world population of Wild Water Buffalo is almost certainly less than 4,000 animals, occupying an area of less than 20,000 km². However, these figures are little more than informed guesses, because any assessment of buffalo numbers is hampered by the difficulty of distinguishing between free-ranging domestic buffaloes, feral buffaloes, truly wild buffaloes, and hybrids between wild and other buffaloes. Individuals of Wild Water Buffalo and Domestic Water Buffalo are difficult to distinguish in some areas, and some domestic populations may be very closely related to (perhaps identical to) Wild Water Buffalo, as in Cambodia, where traditional forms of buffalo husbandry allow herds to range freely in forest areas (Timmins and Ou 2001, R.J. Timmins pers. comm. 2008) or in Kaziranga, India, where in the past cattle camps for grazing wild buffalos existed within the National Park (Choudhury 2010). There have been few detailed analyses of the purity of the presumed remaining Wild Water Buffalo populations, however a benchmark for the purity of the species remains a question. The Domestic Water Buffalo occurs as feral and domesticated populations worldwide, including in sympatry with most remaining populations of Wild Water Buffalo (Grubb 2005, S. Hedges pers comm. 2008). Some feral and domestic populations may well have conservation significance, retaining some of the genetic stock of the wild populations for that particular region, this may be especially true in Indochina because of traditional methods of Water Buffalo husbandry (S. Hedges pers comm. 1994, 2008; Timmins and Ou 2001; R.J. Timmins pers. comm. 2008); and continues to be a matter for debate in the islands of the Sundas and Sri Lanka, where prehistoric presence of Wild Water Buffalo seems likely, but the Holocene history of human manipulation of Domestic Water Buffalo severely clouds the determination of how to treat remaining populations of free living water buffaloes there. 

In India a preliminary investigation comparing genetic traits of the northeastern and the central Indian population suggested that both populations to be related with the Kaziranga samples showing differentiation into three district clades of wild, mixed and feral. The Central Indian population showed no such distinctions (CCMB 2010).

Within India, Choudhury (1994) suggests that there could be about 3,300-3,500 animals in northeast India alone, although later he revised the figure to 2,800-3,000 individuals (Choudhury 2010).

According to Divekar and Bhushan (1988), the total estimate of Wild Buffalo population in Chhattisgarh (Central India) was 104, whereas an estimate by the Forest Department in the year 1986-87 was perhaps an exaggerated 240. Divekar and Bhushan (1988) estimated about 26 Wild Buffaloes were restricted to the Pillur meadow and Pengonda area of Indravati NP, 25 each in Pamed Wildlife Sanctuary and Udanti Wildlife Sanctuary in Chhattisgarh. Ranjitsinh et al. (2002) estimated the population in Udanti as between 42 and 44 with about 25-30 individuals in Indravati National Park. Mishra (2002, 2004) and Mishra and Kotwal (2003) estimated that less than 70 Wild Buffaloes occurred in Central India. There are presently eleven wild buffalo in Udanti with only one female (in captivity) and six wild males and one female  calf. Therefore in two decades or so the population here has shown a massive decline. 

The majority of the Wild Buffalo assemblage in India is restricted to the north-eastern states of India, with Assam accounting for most of the population spread across several protected areas of the state. The state of wild buffalo in northeast India is as follows: 

Assam

Kaziranga National Park: Kaziranga NP constitutes perhaps one of India's most important Wild Buffalo habitats, harbouring the largest aggregate of the species along with a number of flagships, including the Indian one horned rhinoceros and the Asian elephant. Kaziranga NP, spans over 850 Km² over three districts of Assam, and has approximately 2,600 individuals as per the departmental counts in 2011. 

Manas National Park: Situated across two districts of Assam, namely, Baksa and Chirang, and covering around 500 km² of rich habitats, the park is known to harbour around 250 individuals reported during the 2008 census. The adjoining reserve forest areas bound between the national park and the Sankosh river in the west, are believed to hold an additional 30 or more individuals. 

Dibru-Saikhowa Wildlife Sanctuary: Located along the Dibrugarh and Tinsukia districts of Assam, and spanning over 340 km² of riverine tracts and willow swamp forests, the park is thought to shelter more than 400 Wild Buffaloes, as per the 2008 census (Choudhury 2010). 

Besides the above, several other areas in Assam have been reported to harbour Wild Buffalo herds, both in the past as well as in the present. Of these, Borachapori and Laokhowa Wildlife Sanctuaries have been found to harbour around 75 individuals (Choudhury 2010), while Pabha Reserve Forests adjoining Borachapori WLS also harbour dispersing individuals as well as seasonally migrant herds from Borachapori. Additionally, other areas of Assam, such as the Kadam Reserve Forests and the Dhakuakhana area of Lakhimpur district, were both known to hold small populations, but today are known to harbour only a few straggler individuals. In fact a survey in 2009 in Kadam Reserve Forests revealed only a single lone bull in the area. Additionally the Dum Duma Reserve Forests along the Lohit river, have revealed around 13+ Wild Buffaloes by Choudhury (1994), although no earlier records of the species’ presence in this area exits.

Lastly, a number of areas, including the discontinuous patches of forests and grasslands of Kollolua-Jokai, the reserve forests of Batabari and Doadhara, Orang National Park, Pabitora WLS, Gali, Jamjing, Sengajan and Kobo Chapori Reserve Forests of Dhemaji district, the Kakoi, Dulung, as well as the Sonai-Rupai WLS and Pabho Reserve Forest patches of Lakhimpur district, have all been viable habitats of the Wild Buffalo in the past, but have unfortunately lost all traces of the species over the recent past. A few of the above areas however, intermittently harbour either small herd of feral buffaloes of highly decimated remnants of erstwhile populations, mostly represented by few stragglers. 

Meghalaya

Very few historical accounts of the presence of Wild Buffaloes in the state of Meghalaya exist. However, more recent reports suggest that small, low density populations may exist in the Balapakram National Park of the state as well as a few remnant herds in the Nokrek National Park. Choudhury (2010) has suggested that no more than 50 individuals possibly thrive in this part of the landscape, although more systematic species-specific surveys may be needed in these areas to confirm the presence of remnants of the true Wild Buffalo. 

Arunachal Pradesh

A state with an unlikely terrain for the existence of the Wild Buffalo, it is nonetheless thought to bear a few individuals in the D’ering WLS and the Lohit Valley in the Lohit district of the state. Additionally, the Mebo Reserve Forests in East Siang district were also thought to have around 20-25 individuals surviving until the 1960s, although current status suggests that the species is now non-existent. 

West Bengal

Although a number of areas in the state of West Bengal have been reported to have sustained several small subpopulations of Wild Buffalo, especially in the Jalpaiguri and Cooch Behar districts, currently no recognized Wild Buffalo populations exist in the state. The last accounts of the species from the state date back to almost 1928 (Choudhury 2010). 

Bihar

The state is known to have sustained widely distributed populations of the species in the past (Ali 1927), especially in the northern areas of Purnea, Sharsa and Darbhanga districts. Although it is now recognized to have gone extinct from the state, post the 1960’s (Daniel and Grubh 1966).

OTHER COUNTRIES 

Nepal

The only remaining Wild Buffalo population today in Nepal exists in the Koshi-Tappu Wildlife Reserve, with around 220 individuals being tallied in 2008, through a census conducted by the reserve authorities. Besides this, remnant populations were also known to exist in the Chitwan National Park until the 1960s, and also in Bardia National Park until the early 20^th century (Heinen, 1993, 2006, from Choudhury 2010). 

Bangladesh

While numerous supopulations have been reported to have existed across the landscape of Bangladesh over varied periods of time, today almost no reports exist of wild sub-populations or even population remnants. Earlier, several reports on the presence of Wild Buffaloes have come from Fardipur, Chittagong hills, Shirajganj, Dinajpur and Bhola districts. Interestingly, reports from the Mymensingh and Sylhet districts suggest that small populations may have survived up to the earlier part of the twentieth century as well. 

Sri Lanka

Although the Wild Buffaloes in Sri Lanka have been suspected to have originated from feral domestic stocks, owing to the historical absence of Wild Buffalo populations south of the Godavari river in India, the remnant populations today account for a substantial population of almost 2,000 individuals. This aggregate, nonetheless, is isolated largely to the Ruhuna National Park, in the south-eastern part of the country (de Silva et al. 1994). 

Bhutan

Some individuals (about 12) have been seen in Manas National Park (Rob Stenimetz pers obs.) and also in Phipsoo Wildlife Sanctuary (Kaul R. pers. comm). 

Thailand

Thailand today is known to harbour only a small population of Wild Buffaloes. About 35-40 individuals have been reported from the Huay Kha Khaeng WLS in western Thailand (Rob Steinmetz pers. comm). Additionally, small aggregates have also been reported from Khao Soi Dao WLS, although currently no information on their presence exists from here.

Viet Nam

Before 1999, there was reportedly a population in Mom Ray, Viet Nam, but this population no longer exists (Do Tuoc pers. comm. 2006). Rumours still persist of presence in other areas, for example the Satay region (Tordoff et al. 2005, R.J. Timmins pers. comm. 2008). Wild buffaloes of the Cambodian population may wander into western Dak Lak province, but no recent records in Viet Nam have been confirmed to represent wild Water Buffalo (Le Xuan Canh et al. 1997, Eames et al. 2004, Tordoff et al. 2005, R.J. Timmins pers. comm. 2008).

Cambodia

Cambodia perhaps has the smallest population aggregates of the Wild Buffalo among the south-east Asian countries, although it was formerly excluded from the historical distribution range of the species. Camera trapping evidences of presumed wild buffaloes from four locations (7 encounters; 1-3 individuals per photograph) in the core area of Mondulkiri Protected Forest, west of the Srepok river in the year 2005 suggests that the species may be present in some areas (Timmins and Ou 2001, Tordoff et al. 2005, Thompson et al. 2013). However, ongoing camera trapping studies by WWF have failed to detect presence of any buffalos recently. 

Myanmar

There is doubt about the status of with wild buffalo in Myanmar. Seems to be confirmed presence of wild buffalo from the Indo Myanmar border, along the Bulong  river in the Sagaing state (Choudhury 2010). The genetic status of wild buffalo living in the Hukang Valley , north Myanmar is doubtful. 

Lao PDR

The population on Lao PDR is extinct, but the date of local extinction is unknown (Duckworth et al. 1999).

Wild Water Buffalo is very dependent on the availability of water and historically its preferred habitats were low-lying alluvial grasslands including bheels (ox-bow lakes and similar pools left by changing river courses) and their surrounds; river banks, and chaporis (small sandy islands within braided river systems). Riparian forests and woodlands were also used (Lydekker 1924, Prater 1971, Choudhury 1994).

The present distribution of Wild Water Buffalo should not be necessarily regarded as indicating its preference for particular ecotypes because human activities have largely excluded it from many areas.

In Nepal it now occurs only in the seasonally flooded grasslands and mixed forests of the SaptKosi floodplain. Dahmer (1978) provided a description of Buffalo habitat and habitat use in the area.  In Bhutan and Assam, it occurs in alluvial grasslands along the Manas and Brahmaputra rivers—for more details about habitat characteristics in these areas see for example Spillet (1966), Lahan and Sonowal (1973), Jain and Hajra (1975), and Parihar et al. (1986). In the Bastar region of Madhya Pradesh (now Chhattisgarh) Buffalo inhabits tropical dry deciduous forests with an understorey dominated by grasses. It has also been reported to occur in the Sal (Shorea robusta) forests in the area (Daniel and Grubh 1966, Mishra 2003). In Thailand it is now restricted to grasslands, mixed deciduous forest, and dry evergreen forest along rivers in the Huai Kha Khaeng Wildlife Sanctuary (Nakhasathien and Stewart-Cox 1990; Uicharoensak 1992). In Sri Lanka Buffalo is particularly associated with grasslands, scrubby grasslands, and discontinuous forest areas. During the dry season it spends more of its time in forested areas (Eisenberg and Lockhart 1972, Ashby and Santiapillai 1983).

Buffaloe spend considerable amounts of their time lying and wallowing in pools of water and/or mud. Where large pools of water are not available, Buffaloes will make use of smaller depressions, providing some moisture remains which they can churn to a muddy consistency. Wallowing has a thermoregulatory function. Buffaloes have fewer sweat glands per unit area of skin than do cattle and evaporative cooling through sweating is of little importance. Mud is considered more effective at cooling animals than is clean water because the water that is held in the mud evaporates slowly and so prolongs the cooling effect. Some reports suggest that for species such as Buffalo wallowing is essential for their survival but Tulloch’s (1970) studies of feral buffaloes in Australia do not support this conclusion; instead his results indicate that when buffaloes are deprived of wallows they behave more like cattle and seek shade (Tulloch 1970). Running water is also used for bathing (Lekagul and McNeely 1977). Wallowing has the additional function of providing a thick coating of mud on the body that protects the animals from insect bites.

Buffaloes are very loyal to traditional trails and use the same routes repeatedly and this can lead to considerable erosion, particularly where trails cut down to river courses.

Information on the habitat use of feral Bubalus bubalis in Australia is provided by Tulloch (1969, 1970, 1979). Although, most of the habitat of Wild Buffalo is swampy, in Central India hard-ground habitats are used by Wild Buffalo where most of the water sources are human-made. The animals prefer dense forest during day time for grazing/browsing while they may feed in open forest with patchy grasslands during night. The use of water bodies is more common in the evening and late night due to human pressures in Udanti WLS (WTI 2012). 

Research in both Assam and Sri Lanka has shown that herd movements are closely related to climatic factors, as one would expect from an animal so dependent on the availability of water. During the wet season in both regions Wild Water Buffalo tends to be widely dispersed and occur in small herds, but with the onset of the dry season the buffaloes tend to gather at permanent water holes and large aggregations can develop ( Ashby and Santiapillai 1983). In Wilpattu NP in Sri Lanka the herds of female Buffaloes and their offspring that are thought to be of the wild-type (the ‘forest buffalo’ of Eisenberg and Lockhart 1972) remain attached to certain areas for long periods (i.e. they have well-defined home-ranges). As water sources begin to dry-out and forage availability declines these ranges may shift but they return to their original home ranges with the arrival of the rains. Males, especially subadults and the younger adults, tend to move over considerable distances during the mating season. A similar pattern of seasonal movements and site attachment has been reported from elsewhere in Sri Lanka particularly Ruhuna NP (Eisenberg and Lockhart 1972, Ashby and Santiapillai 1983). The movements of animal are individually or in herds. The home range of Wild Water Buffalo in Udanti sanctuary is almost fixed and ranges between 15 and 20 km², mostly around permanent water holes where there is no human disturbance (Mishra 2001, 2003). 

Little published information is available about the daily movements of Wild Water Buffalo. In undisturbed areas it is reported to feed in the open at dusk and dawn, moving into cover and/or lying in wallows during the heat of the day. Nevertheless (feral) buffaloes will feed in open areas at mid-day, returning at intervals to shade and/or wallows. Daily movements of feral buffaloes are often rather predictable. Certain places within the home ranges of (feral) buffaloes are visited very frequently; these include latrines, rest areas (‘camps’), pools, mud-wallows, and particular trees, often close to wallows, against which buffaloes rub themselves (‘rubbing trees’). Obvious trails join these frequently used features. Wild Water Buffaloes are generally averse to human disturbance and seek refuge in the remotest habitats, the solitary bulls who seek domestic buffaloes for mating being an exception.  In both Indravati and Pamed the Wild Water Buffalo prefers to come out during night only, whereas it is normally diurnal.  Kotapalli villagers near Pamed reported buffaloes coming at 05.00 hours to the waterhole and disappearing after dawn. 

The strong attachment of Wild Water Buffalo to known ranges can have unfortunate consequences particularly when water and/or food are scarce. Feral buffaloes (in Australia) have been known to die of thirst rather than walk approximately five kilometres to a large lagoon used by other buffaloes (Tulloch 1970). They are thought to range as high as 1500m asl (S. Hedges pers. comm. to Choudury 2014) in the Western Ghats.

Little has been published on the diet of wild (or feral) Bubalus bubalis. It is probably a grazer by preference, feeding mainly on grasses when available, but it also eat herbs, fruits, and bark as well as browsing trees and shrubs. Daniel and Grubh (1966) list Cynodon dactylon, Themeda quadrivalvis, and Coix sp. as grasses that are known to be eaten by Wild Water Buffalo in India. They also saw Buffalo feeding on the sedge Cyperus corymbosus. Dahmer (1978), Shrestha (1981), and Kushwaha (1986) provide a little information about the diet of Buffalo in Nepal. Wild Water Buffalo also feed on crops, including rice, sugar cane, and jute, sometimes causing considerable damage (Lekagul and McNeely 1977, Kushwaha 1986, Bauer 1987). 

Wild Water Buffalo is reported to be a selective feeder and to wander long distances in the course of grazing (Daniel and Grubh 1966). Feral buffaloes in Australia also graze selectively  according to Tulloch et al. (1986) but Moran (1987) reported that they are far less selective than are Brahman cattle. Buffaloes in Sri Lanka are reported to eat nearly anything in their path (Ashby and Santiapillai 1983). Wild Water Buffalo seems to have a higher tolerance for saline water than do many mammals and will drink from brackish pools (Eisenberg and Lockhart 1972).

The Wild Water Buffalo may invade farmland to depredate crops like rice, Dolichos biflorus, Vicoa mungo and Brassica campestris (Mishra 2002, 2004; WTI 2009).

Typically, it forms maternal groups of loosely structured herds, typically containing 10–20, but up to 100, individuals, year round. Adult males form bachelor herds of up to 10 individuals, with older males often solitary. The species exhibits a polygynous mating system, with females typically giving birth to single offspring, although twins are possible. It is a seasonal breeder in most of its range, typically in October and November, however, some populations breed year round. Its gestation lasts 10-11 months, with an interbirth interval of one year. Age at sexual maturity is 18 months for males, and three years for females. The maximum known lifespan is 25 years in the wild (Nowak 1999).

The major threats to Wild Water Buffalo are loss of genetic diversity due to introgression with domestic and feral buffaloes, as well as threats from hunting, and disease from domestic livestock. 

Genetic Factors

It is highly likely that the existence of Wild Water Buffalo is being threatened by genetic introgression from domestic buffaloes in Nepal (Flamand et al. 2003). In India, hybridisation is thought to be evident in the North-east where wild buffaloes are known to hybridise with Khunti (cattle camp) buffaloes which were grazed within the park prior to their eviction (Muley 2001). However, it was suggested that there is a genetic differentiation between wild and domestic/feral buffaloes in Kaziranga National Park, and that the Wild Water Buffalo is comparable to Wild Water Buffalo in central India (CCMB 2010). Although, the central Indian buffaloes do live along with hybrid and feral buffaloes, so introgression could have occurred to some degree in both locations. Introgression is likely to take place throughout the range wherever wild and domestic buffalo come into contact. It is estimated that more than 90% of the population exists in the vicinity of considerable populations of Domestic Water Buffalo (See Table 1. in the Supporting Information: B. arnee additional information populations in vicinity of Domestic Water Buffalo). This means there is a the risk of hybridisation is high. As the wild populations shrink  and become fragmented the risk of hybridisation increases exponentially (within a few generations). Given the fragmented nature of the populations and the proximity of Domestic Water Buffalo, and applying the precautionary principle, the truly pure Wild Water Buffalo population could half of the current estimated population, or less. 

In evolutionary terms wild and domesticated water buffaloes are closely related, being separated by perhaps as little as 5,000 years (Cockrill 1974, S. Hedges in prep). The phylogeny of buffaloes has not been fully resolved and it is unclear as to the number of domestication events that have occurred in the case of this species. At least two separate domestications, one for ‘swamp’ and one for ‘river’ type buffalo are thought to have taken place (Lau et al. 1998, Kumar et al. 2007, Yindee et al. 2010, Babar et al. 2012) Additionally, the practise in some villages, of allowing wild buffalo to sire calves with domestics (Flamand et al. 2003) may have resulted in continued gene flow between the two, at least in one direction. The situation is analogous to other species which are the progenitors of domesticated forms especially that of the wild cat Felis (Beaumont et al. 2001. This may be particularly the case in Indochina where traditional methods of Domestic Water Buffalo husbandry allowed animals to wander freely for the majority of the year, often in natural habitat over 5 km from villages; indeed, it is often difficult to determine whether animals in forest areas are domesticated or truly feral; as such before hunting largely eliminated the Wild Water Buffalo population there must have been much contact between the two species, and presumably a great deal of opportunity for introgression, albeit perhaps strongly in one direction, given the male-dominated mating system of water buffalo (Timmins and Ou 2001, R.J Timmins in litt. 2013). Domestic Water Buffalo in ‘frontier’ rural areas of Indochina often show a strong similarity to published and other widely available images of Thai and Indian Wild Water Buffaloes (R. J Timmins in litt. 2013), while Clark (undated) wrote that neither local people nor experienced hunters could distinguish Wild and Domestic Water Buffaloes on the basis of physical appearance, on the Lagna (La Ngà) River alluvial plains of southern Vietnam where the two occurred together, and that they were only identifiable on the basis of their behaviour: further evidence that the genepools of Indochinese Domestic Water Buffalo and Wild Water Buffalo are probably very close. 

Whilst it is likely that the genetic integrity of Wild Water Buffalo is threatened by introgression from the domestic form, the risk of inbreeding within the dwindling populations of Wild Buffalo must not be underestimated as a threat to its survival. Small populations are at risk of inbreeding depression (i.e. lowered reproductive fitness) which can in turn lead to further population decline (Hendrick and Kalinowski 2000). The small population size of Wild Water Buffalo in central India (34–42 individuals), means that there is a high risk of extinction through demographic factors (WTI 2010). For example, stochastic variation in demographic rates causes small populations to fluctuate randomly in size. Wild Water Buffalo in some populations may face the risk of inbreeding effects through low population numbers. Whilst introgression with domestic forms may paradoxically have the ability to mitigate some of the inbreeding risk by injecting genetic diversity, it carries with it the risk of erosion of the genetic diversity unique to the wild form (as mentioned above). 

A challenge to the captive breeding of wild buffalo will be balancing the relative risks of inbreeding and out breeding when choosing candidate animals for a breeding programme. This is likely to require a detailed level of genetic screening, the technical challenges of which must not be underestimated (Randi et al. 2008). Since introgressed buffaloes may outnumber non-introgressed Wild Buffaloes considerably, it may be necessary to view introgressed animals as a vital genetic resource from which wild genetic diversity can be recaptured through controlled backcrossing, as opposed to viewing them as animals tainted by domestic introgression. 

Hunting

Wild Buffaloes have for long been hunted ritually, owing to their formidable nature and horns. Besides sport hunting that was prolific until the 1960s, hunting for meat is also a popular practice in several parts of North-east India as well as in many South-east Asian countries. With legal protection of Wild Water Buffalo in India, Bhutan, Nepal, and Thailand (Hedges et al. 2008), the severity of hunting may have reduced over the recent past. Although poaching for wild meat is still a real threat to any remaining Wild Water Buffalo populations in South-east Asia, especially Cambodia and Myanmar, trophy hunting may be the most worrying threat, especially if general knowledge of the existence of remnant populations grows, as the economic growth in the region has seen massive growth in exploitation of valuable natural resources, such as wildlife-derived status symbols (R.J. Timmins in litt. 2013). 

However, Paradh, traditional community hunting, still persists in some part of central India (Mishra 2000). Also, extensive droughts and habitat fragmentation and degradation have caused Wild Water Buffaloes habitually to invade and raid crops, leading to repercussions by local villagers. This perhaps single-handedly has led to a severe population decline in many states such as in Chhattisgarh. 

Disease

One of the persistent threats to wildlife is the threat of disease outbreaks from livestock raised in the surrounding villages. For instance, several sub-populations of  another large bovid, the Gaur (Bos gaurus), in peninsular India, were known to have been almost exterminated through a severe outbreak of Rinderpest in 1968 (Krishnan 1972). Similarly, Wild Water Buffaloes are also susceptible to a number of cattle diseases, and therefore, where very small populations remain, they face the risks of extinction due to disease. 

Habitat Loss and Degradation:

Wild Buffaloes like most other large herbivores, require large spaces with adequate food and water supply to survive which is negatively impacted by fragmentation and degradation of forest and grassland areas. Although most cattle camps have been removed from within Kaziranga in Assam, extensive livestock grazing in Chhattisgarh may place the Wild Water Buffaloes there in situations of severe resource competition. This is because of pasture depletion and lack of water resources, which could lead to direct conflict. 

Local community and insurgency

There are areas in central India where Wild Water Buffalo exists and there are difficulties of insurgency and law and order problems. The result is that in such areas, conservation is often difficult to achieve without the support of local people. 

Probably one of the most significant constraints, is an under appreciation even amongst conservation organisations of the importance, significance and plight of Wild Water Buffalo populations (Choudhury 2010). This is exemplified by the situation in Cambodia where next-to-no species-specific action has been taken for Wild Water Buffalo, despite the known presence of a remnant population in one area, with to date the fear that the population may have declined and possibly even been lost (R. J. Timmins in litt. 2013).

The Wild Water Buffalo is hunted for food, sport, and handicrafts products. Domestic Water Buffalo is considered a separate species, so its uses are not considered here, and additionally uses/markets for derivatives of the two species are likely to be largely independent of one another.

Wild Water Buffalo is included in CITES under Appendix III (Nepal). It is legally protected in Bhutan, India, Nepal, and Thailand. The Cambodia population was a major factor in the decision to place further protection on the area, now designated as Mondulkiri Protection Forest, and a significant factor in the decision to establish the Srepok Wilderness Area Project of the Cambodian Department of Forestry and WWF (Goodman et al. 2003; R. J. Timmins pers. comm. 2008).

Most of the known populations are within protected areas. In Myanmar, which retains true lowland floodplains in near-natural state in the Hukaung Valley, the protected area system originally almost entirely excluded floodplain grasslands. The inclusion of some areas is now under consideration, and would benefit this species. However, the outcome is far from certain (J.W. Duckworth pers. comm. 2006).

Most remaining populations still require practical protection from hunting (especially those in Thailand and Cambodia, and Myanmar if still extant), but probably the greater threat in South Asia is protection from contact with other domestic bovines, especially Domestic Water Buffalo.

There is an urgent need to evaluate the integrity of wild-living buffalo populations, including those generally taken as being truly wild and those living as wild animals within the native range, using habitat typical of wild animals, and which have lived outside even occasional husbandry for a long time, in order to determine populations of conservation priority. This should involve the assessment of the relationship of such populations in the context of obvious domestic lineages, especially those in close proximity to wild populations. Such an approach should use multiple genetic markers in addition to an assessment of morphological characteristics.

Surveys to investigate current status of wild-living populations are needed in Myanmar and perhaps the Satay district of Viet Nam.

In India, a Conservation Action Plan has been developed recently seeking to recover the Wild Water Buffalo in central India. At local levels, both the state governments of Chhattisgarh and Maharashtra which hold the last remains of the central Indian Wild Water Buffalo populations are engaged in conservation of this species with the former adopting it as a state animal.